Lumpy was a nickname given to a large stocky man ( 6'-6" 400lbs ) in upstate NY and when he was called upon by his friends to settle a depute they called him the Lumpinator as a reference to the terminator
hey lumpinator come here and tell this guy to leave
you better watch what u say or i'll have to sick the Lumpinator on u
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.